I'm thinking my FIL might like to buy a painting while in Rome. I have read that a lot of the paintings in Piazza Navona are not actually painted by the people there, even if it looks like they're currently working on a painting. Should I just assume that these paintings are not original and pay with that in mind? Is it normal to haggle with the seller? I'd really hate for him to spend a good amount of money on something that isn't actually worth that much but I know nothing about art so it'd be hard for me to guess at value.